QUALITY ASSESSMENT OF WATER FROM THREE SELECTED RIVERS IN JALINGO METROPOLIS, TARABA STATE

Abstract

This study is poised to investigate the physicochemical and bacteriological parameters of three rivers (Karofi, Nukkai and Donga) in Jalingo Metropolis, Taraba State. The parameters under study were determined following standard methods: The pH (7.20±0.70 - 7.98±2.40), temperature (24.5±1.30 - 25.3±1.30
oC), dissolved oxygen (7.38 ±0.70 - 8.72±0.56 mg/L) and key ionic indicators
such as alkalinity (40±3.33 - 80±6.76 mg/L), total suspended solids (25±0.00 -
45±0.00 mg/L), electrical conductivity (102.4±10.0 - 390 ±11.32 μS/cm), chloride (101±6.79 - 112±9.20mg/L), nitrite (0.00±0.00 - 0.10±0.00 mg/L), sulphate (4.00±0.50 - 6.00±0.52 mg/L) and ammonia (0.00±0.00 - 0.01±0.00 mg/L) were within permissible limits of World Health Organization. However, turbidity levels (46.0±3.4 - 77.6±4.07 NTU) were significantly elevated across all samples an indication of high particulate contamination. Phosphate concentration (17.97±0.98 - 51.39±4.50 mg/L) exceeded the recommended limits, suggesting nutrient loading likely linked to faecal contamination. Urea concentration was in the range of 0.16±0.00 - 0.21±0.00 mg/L, biochemical oxygen demand values (50±1.24 - 82.5±7.72 mg/L) were notably high, depicting sustained organic pollution. Total and dissolved organic carbon (TOC and DOC), BOD and COD values were also found to be above the permissible limits. Oil and grease levels were within the safe limit. Nitrate values were within the safe limit except for river Karofi that had a high value of (17.97±1.24 mg/L). While arsenic, cobalt, lead and selenium were not detected, metals such as iron and aluminium were present in concentrations that may pose health risk. Chromium levels were within the safe limits except for river Karofi (2.10±0.00 mg/L) value that was above the safe level. Nickel and zinc concentrations for water from the three rivers were found to be within the permissible safe limits. Manganese levels were within the safe limit except for river Donga with high value (2.10±0.00 mg/L) and above the safety limit. Result of bacteriological analysis showed elevated coliform and Escherichia coli counts, with rivers (Nukkai and Donga) depicting unquantifiable levels of coliform, an indication of faecal pollution. The Canadian Council of Ministers of the Environment Water Quality Index indicates that the water from the three rivers are significantly impaired (Donga river = 31.10 %, Karofi river = 28.25 % and Nukkai river = 19.77 %) and ranked as poor. Water from any of these sources needs treatment before it can be safe for domestic use or drinking purposes.